Added budget entity

PostFundManagement.Domain/Configuration/Budget.cs

@@ -0,0 +1,36 @@
+namespace PostFundManagement.Domain.Configuration;
+
+public sealed class Budget : IEntityTypeConfiguration<Entities.Budget>
+{
+    public void Configure(EntityTypeBuilder<Entities.Budget> builder)
+    {
+        builder.ToTable(nameof(Entities.Budget).Pluralize());
+
+        builder.HasKey(pk => pk.Id);
+        builder.Property(f => f.ProjectId).IsRequired();
+        builder.Property(f => f.CreatedBy).IsRequired();
+        builder.Property(f => f.ApprovedBy).IsRequired(false);
+        builder.Property(f => f.CreatedAt).IsRequired().HasDefaultValueSql("now()");
+        builder.Property(f => f.UpdatedAt).IsRequired(false);
+        builder.Property(f => f.Name).IsRequired().HasMaxLength(256);
+        builder.Property(f => f.Amount).IsRequired().HasPrecision(18, 2);
+
+        builder.HasOne(f => f.Project)
+            .WithMany()
+            .HasForeignKey(fk => fk.ProjectId)
+            .IsRequired()
+            .OnDelete(DeleteBehavior.Restrict);
+
+        builder.HasOne(f => f.Creator)
+            .WithMany()
+            .HasForeignKey(fk => fk.CreatedBy)
+            .IsRequired()
+            .OnDelete(DeleteBehavior.NoAction);
+
+        builder.HasOne(f => f.Approver)
+            .WithMany()
+            .HasForeignKey(fk => fk.ApprovedBy)
+            .IsRequired(false)
+            .OnDelete(DeleteBehavior.NoAction);
+    }
+}

PostFundManagement.Domain/Entities/Budget.cs

@@ -0,0 +1,10 @@
+namespace PostFundManagement.Domain.Entities;
+
+public class Budget : Models.Budget
+{
+    public virtual Project? Project { get; set; }
+
+    public virtual User? Creator { get; set; }
+
+    public virtual User? Approver { get; set; }
+}

PostFundManagement.Infrastructure/Database/ApplicationDbContext.cs

@@ -4,6 +4,8 @@ namespace PostFundManagement.Infrastructure.Database;
 
 public sealed class ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : DbContext(options)
 {
+    public DbSet<Budget> Budgets => Set<Budget>();
+
     public DbSet<Contract> Contracts => Set<Contract>();
 
     public DbSet<Award> Awards => Set<Award>();